The present invention relates to the subject of shielding strips, especially RFI/EMI shielding strips used widely in connection with the construction of cabinets for computer equipment, for example.
In connection with the design of cabinetry for computer equipment and the like, it is conventional practice to utilize shielding strip elements around the panel openings for such cabinetry, to prevent the escape of electromagnetic radiation. A particularly advantageous form of such shielding strip material is described and claimed in the Busby U.S. Pat. No. 4,652,695, owned by Pawling Corporation, Pawling, N.Y. The present invention is particularly applicable to shielding strip material of that type, but is not necessarily limited thereto.
The shielding strip illustrated in the Busby U.S. Pat. No. 4,652,695 comprises an elongated, more or less continuous mounting strip of clip-like configuration, formed of a conductive metal, such as stainless steel. The mounting strip is adapted to be attached to the edge of the sheet metal material forming a door or other panel opening for a typical computer cabinet.
Attached to the clip-like mounting strip is a continuous length of resilient core material, advantageously a hollow tubular core strip of a suitably resilient elastomeric material. A conductive metal mesh material is wrapped about the central core strip and is anchored to the clip-like mounting strip. Reference may be had to the before-mentioned Busby U.S. Pat. No. 4,652,695 for additional details of construction of a particularly preferred form of mesh-clad shielding strip. However, it is to be particularly understood, that the present invention is not limited to the strip illustrated and described in the Busby patent.
In a mesh-clad shielding strip, the mesh material advantageously is in the form of a knitted mesh of metallic yarn, such as soft "MONEL" wire. The knitted mesh material is either constructed about the resilient core strip in the first instance or, as in the before-mentioned Busby patent, is wrapped around the core after the knitting process.
Typically, mesh-clad shielding strips are manufactured in lengths significantly greater than those used in the production of shielded cabinets. Accordingly, subsequent to manufacturing, the shielding strips are cut to predetermined length for installation. The cutting operation leaves a relatively ragged end, which is not only unsightly, but results in many loose ends of the knitted wire, which can unravel, snag, etc. Accordingly, it has been typical practice to coat the severed ends of mesh-clad shielding strip with a suitable polymer composition, to seal the ragged ends of the mesh. This has proven to be an expensive and time-consuming operation.
In accordance with the present invention, a novel and improved end clip device is provided, which can be quickly snapped over the end of a cut shielding strip section to cover the unsightly ragged end of the mesh-clad core and also to effectively secure the mesh material against unraveling and/or snagging. Pursuant to the invention, the terminating clip is formed of a thin strip of resilient material, advantageously a suitable grade of stainless steel, which is extremely economical to produce and simple and easy to apply to the cut sections of shielding strip.
Pursuant to one aspect of the invention, the end clip may be in effect "wrapped" about the cut end of the shielding strip, partially compressing the mesh-clad core strip, advantageously to approximately one-half of its original height. In this respect, it is contemplated that, when the shielding strip is installed, it will be compressed somewhat upon closure of the door or panel on which it is installed, and the design of the end clip is such that it does not interfere with this process.
For a better understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings.